Imagine forcing a pillow over your face. Hard to breathe right? That's what a dirty filter does to your Hitachi AC blower; the blower has to to work longer and harder to circulate air through the filter. This causes the blower to draw more electricity and trip the breaker.
Your Hitachi AC system has an inside unit and an outside unit. The inside unit absorbs heat from your air using refrigerant. That refrigerant flows to the outside unit to disperse the heat.
However, the outside unit can't disperse heat well if it's super dirty because dirt is an insulator. So the Hitachi AC runs and runs trying to disperse that heat outside until—click—the breaker trips due to drawing too much current.
The issue may not be with the Hitachi AC itself but rather with the breaker.Wires connected to the breaker may be loose or the breaker itself may be bad and needs replacing. This is a relatively inexpensive fix.
Electric motors in your Hitachi AC can run for hours and hours and can take quite a bit of abuse. But if a motor runs hot for too long, the wire insulation can break down, leading to an electrical "short."
The heart of your Hitachi AC system is the compressor. It pulls tons of electricity when it starts up.
Unfortunately, as the compressor ages, it has trouble starting (called hard starting) and pulls even more electricity, causing the breaker to trip as a result.
A "grounded compressor" or “compressor short to ground” means that an electrical winding inside the compressor has broken and hit the side of the compressor. This causes a direct short to ground, igniting the oil and causing a burnout. And, of course, the circuit breaker trips due to the sudden current surge.